SinkholeOdds

Sinkhole risk in Niagara County, NY: Mostly deep or small

Mostly deep or small

Some soluble rock, mostly deeply buried or in a small share of the county.

On soluble rock
18%
At or near the surface
0%
Buried under cover
18%

What to do about a house in Niagara County

Sinkholes are uncommon here; watch for new depressions after heavy rain or leaking pipes.

That works out to roughly 95 of Niagara County's 522 square miles on soluble rock. With about 209,570 residents (401 per square mile), homes are spread across towns and farmland, and a mapped unit may or may not reach the developed parts. The figures come from 280 map points about 1.4 miles apart, so a pocket smaller than that can be missed or overstated.

Worth reading for this county: why gypsum and salt move faster than limestone, and why the 18% under cover still counts.

Counties around Niagara County

The nearest county rated sinkhole country is Union County, PA, about 183 miles southeast. 4 of the 6 closest counties land in the same band, so this is a regional pattern rather than a local quirk.

The rock underneath

The largest mapped soluble unit here is the Camillus, Syracuse, and Vernon Formations (shale), Upper Silurian in age, covering about 16% of the county. Next is the Irondequoit Limestone thru Kodak Sandstone at 1%.

The county also lies over the Michigan Basin; Ohio Basin; Appalachian Basin, a deep salt or gypsum basin. Deep beds rarely cause surface collapse on their own, but wells and mining into them have.

Against the rest of New York

Niagara County ranks 34 of 62 in New York for soluble rock at the surface, and sits above 0% of US counties on that measure.